The Third Italian War of Independence (
Italian: Terza Guerra d'Indipendenza Italiana) was a war between the
Kingdom of Italy and the
Austrian Empire fought between June and August 1866. The conflict paralleled the
Austro-Prussian War and, like that war, ended in an Austrian defeat, with Austria conceding the region of
Venetia to Italy. Italy's acquisition of this wealthy and populous territory represented a major step in the process of
Italian unification.

Background

Victor Emmanuel II of Savoy had been crowned
King of Italy on 17 March 1861 but did not control
Venetia or the much reduced
Papal States. The situation of the Irredente (a later Italian term for part of the country under foreign domination, literally meaning un-redeemed) was an unceasing source of tension in the domestic politics of the newly created Kingdom, as well as being a cornerstone of its foreign policy.

The first attempt to seize Rome was orchestrated by
Giuseppe Garibaldi in 1862. Confident in the King's neutrality, he set sail from
Genoa to
Palermo. Collecting 1,200 volunteers, he sailed from
Catania and landed at
Melito, in
Calabria, on 24 August to reach Mount
Aspromonte, with the intention to travel northwards up the peninsula to Rome. The Piedmontese General
Enrico Cialdini, however, sent a division under Colonel Pallavicino to stop the volunteer army. Garibaldi himself was wounded in the
ensuing battle, and taken prisoner along with his men.[3]

The increasing discord between
Austria and
Prussia over the
German Question turned into open war in 1866, offering Italy an occasion to capture
Venetia. On 8 April 1866 the Italian government signed a military alliance with Prussia,[4] through the mediation of Emperor
Napoleon III of France. Italian armies, led by General
Alfonso Ferrero La Marmora, were to engage the Austrians on the southern front. Simultaneously, taking advantage of their perceived naval superiority, the Italians planned to threaten the
Dalmatian coast and seize
Trieste.[5]